Integrated 3-D Imaging Facilitates Human Face Transplantation

Devastating injuries or defects of the face are extremely challenging, if not impossible, to satisfactorily reconstruct by traditional surgical techniques. In face transplantation, facial tissue from a donor is transferred to reconstruct the defect, restore essential life-sustaining functions − such as breathing, chewing and speaking − and, above all, re-establish normal human appearance.

"This surgery is for patients with devastating injuries to the face, who have lost their ability to smell, eat and engage socially and have no other conventional treatment options," said Doctor Vijay S. Gorantla of UPMC.

Clearly defining and understanding the complex tissue deficits and defects that accompany devastating facial injuries like electric burns, blast wounds and accidental trauma are critical for both technical success and objective analysis of the return of function after face transplantation.

Medical imaging plays a major role in the entire spectrum of face transplantation, ranging from patient selection, donor and recipient surgical planning, and postoperative assessment of returning motor and sensory function. Face transplantation is a lengthy, complicated procedure that involves reconstruction of multiple tissues − such as skin, muscle, blood vessels, nerves and bone − by a team of surgeons.

Using sophisticated computer modelling software researchers integrated information from 3-D CT, CT angiography, MRI and high-definition tractography to create a 3-D model of the patient's head and neck anatomy. The same type of modelling technology is often used in movies to animate computer-generated characters with detailed three-dimensional human features and realistic expressions.

"We have integrated data from multiple imaging sources into a single 3-D representation that allows for real-time user interaction and modification," Doctor Darren M. Smith said. "In assessing eligibility for this procedure, it is critical to understand whether the patient has enough blood vessels and bone structure to support new facial tissue. This 3-D modelling helps us customise the procedure to the patient's individual anatomy so that the donor tissue will fit like a puzzle piece onto the patient's face."

Using computer modelling, the team also overlaid the patient model with a polygon mesh of a generic human face and then customised it to the recipient facial anatomy. Smith said the ability to manipulate this 3-D facial envelope over the residual face model allows the entire surgical team to participate in planning exactly where bone, blood vessel and nerves will be cut and connected, as well as to evaluate the outcomes of reconstructive transplantation, including nerve regeneration within the transplanted facial tissue.